Electrical connector with shielding

ABSTRACT

The printed circuit board connector element has a plurality of signal contacts (2) arranged grid-like in a spring clip (1) and a shielding unit (3) that contains a first and second ground lamina (4, 5) that are conductively connected via a bridge (6) that have a first impressible ground terminal (7) projecting from it. The ground laminae (4, 5) respectively extend over all intervening signal contacts (2) of a column, whereby a shielding unit is provided for only every second signal contact column. As a result thereof, only one signal contact per two columns need be occupied with ground or, respectively, only one shielding unit per two columns is required for the complete shielding of all columns.

SPECIFICATION BACKGROUND OF THE INVENTION

The invention is directed to a printed circuit board connector elementwith a plurality of signal contacts arranged grid-like in columns androws in a spring clip of insulator, and with a shielding unit thatcontains a first and second ground lamina that are conductive, arearranged at opposite sides of at least one of the signal contacts andthat are conductively connected to one another via a bridge, whereby theshielding unit comprises a first ground terminal projecting from it thatcan be conductively connected to the printed circuit board.

Such a printed circuit board connector element is disclosed by Germanreference DE 44 10 047 A1.

Low-frequency printed circuit board plug connectors are beingincreasingly operated with faster digital signals. The extremely steepleading signal edges correspond to high frequencies. Problems with thesignal transmission quality thereby arise; in particular, undesiredcross-talk effects arise between neighboring signal contacts. On theother hand, it is foreseeable that both assemblies with very fastsignals as well as assemblies with signals that are less fast will beemployed in future devices. This gives rise to the need to connect andoperate both frequency-optimized spring clips as well as standard springclips by plugging to standard blade connector on the device backplane.

The problem of cross-talk can be conventionally solved in that thesignals are conducted over only every second contact, whereas theintervening contacts are occupied with ground. In this solution,however, the plurality of terminals usable for the signal transmissionis drastically reduced, so that it seems poorly suited for applicationswith a high signal density.

German reference DE 40 40 551 C2 discloses that a cross-talk betweenterminals neighboring one another in neighboring, vertical rows beprevented by inserting a shielding element between the vertical terminalrows of a spring clip. What is disadvantageous about this solution,however, that only three of the five available contact rows are usablefor signals and two rows are occupied with ground.

A shielding unit with two bulkhead sheets connected by a bridge is infact known from the initially cited Published Application. However, onlyconnector elements--see FIGS. 2, 7 and 8--wherein a first, front half ofthe signal contacts of a column is directly shielded by the shieldingunit belonging to this column are proposed therein. The other half ofthe column is shielded by two further shielding elements that arearranged at the columns adjacent at the left and right and respectivelyextend thereat only along the second, back half of the signal contacts.This known design solution has the disadvantage that respectively onesignal contact in every column must be occupied with ground since ashielding unit is provided for each column, which is already involved interms of fabrication technology. What is also disadvantageous in view ofmanufacture is the fact that two different shielding elements areemployed as well as the complicated assembly sequence that derivesoverall. As viewed in terms of the functioning of the shielding, theknown solution is problematical insofar as each shielding unit thereinis connectable to the printed circuit board with only one terminal toground, as a result whereof the reflux current cannot follow the idealpath.

SUMMARY OF THE INVENTION

The present invention is based on the object of creating an improvedplug connector of the species initially cited that, particularly,reliably prevents cross-talk, that causes structural changes only at oneconnector element, the spring clip, and that is simple to manufacture.

In a connector element of the species initially cited, this object isinventively achieved in that

c) the ground laminae respectively extend over all intervening signalcontacts of a column;

d) and a shielding element is provided only for every second signalcontact column.

In general terms the present invention is a printed circuit boardconnector element having a plurality of signal contacts arrangedgrid-like in columns and rows in a spring clip of an insulator. Ashielding unit contains a first and second ground lamina that areconductive, are arranged at opposite sides of at least one of the signalcontacts and that are conductively connected to one another via abridge. The shielding unit has a first ground terminal projecting fromit that can be conductively connected to the printed circuit board. Theground laminae respectively extend over all intervening signal contactsof a column. A shielding unit is provided only for every second signalcontact column.

The shielding unit contains a spring contact that assumes the locationof a signal contact of the respective column. The spring contact is heldby insulation displacement contacts respectively fashioned opposite atthe ends of the ground laminae at the blade connector side.

The spring contact is fashioned with lateral shoulder lying inlongitudinal direction of the spring clip. The shoulders are held by theinsulation displacement contacts.

A broad lug lying in longitudinal direction of the spring clip isfashioned at that end of a contact leg of the spring contact lying atthe blade connector side. The lug is respectively held at the sides byan insulation displacement contact.

The middle signal contact of the respective column is replaced by thespring contact and by the ground terminal.

At least a second impressible ground contact is fashioned at theshielding unit.

The bridge is arranged at that end lying opposite the end of theshielding unit at the blade connector side. The press-in terminals ofthe respective signal contact column extend column-like between thefirst ground terminal lying behind these press-in terminals and thefurther ground terminals lying in front of these press-in terminals.

The press-in terminals and the impressible ground terminals extend intoa printed circuit board. The terminal bores for the ground terminalsrespectively lie on the printed circuit board in a row in front of andbehind the terminal bores for the press-in terminals of the signalcontacts.

A blade connector can be provided for a further printed circuit boardconnectable thereto by plugging.

BRIEF DESCRIPTION OF THE DRAWINGS

The features of the present invention which are believed to be novel,are set forth with particularity in the appended claims. The invention,together with further objects and advantages, may best be understood byreference to the following description taken in conjunction with theaccompanying drawings, in the several Figures of which like referencenumerals identify like elements, and in which:

FIG. 1 a perspective view of a shielding unit with a ground springcontact that has not yet been inserted and of a spring clip; FIG. 2 afurther embodiment of a shielding unit in an illustration similar toFIG. 1;

FIG. 3 a schematic plan view onto a part of a printed circuit boardconnected to the connector element;

FIG. 4 another embodiment of the printed circuit board according to FIG.3.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 1, top, shows an inventive shielding unit 3 that comprises toparallel grounding laminae 4 and 5 that are conductively connected toone another at the end of the shielding unit at the blade connectorside--i.e. at the very top in FIG. 1--via a bridge 6 that comprises apress-in, first ground terminal 7 projecting from it. An insulationdisplacement contact 9 fashioned at the ground lamina 4 is indicated atthe end of the shielding unit 3 at the blade connector side. Due to theperspective that has been selected, the identically fashioned insulationdisplacement contact 10 lying opposite at the ground lamina 5 cannot beseen.

The present invention fundamentally combats cross-talk with groundlaminae that are attached between the signal contacts of a column in thespring clip. These ground laminae must make a low-impedance contact withone or more pin contacts on the device backplane. This contact mustoccur as far as possible to the front in the spring clip so that theinduced currents can be neutralized on the shortest paths. The shieldingplates fashioned as ground laminae reduce inductive and capacitativecross-talk and act as low-induction connecting paths to ground in orderto minimize the signal path impedance. They improve the transmissionquality of the signal.

For producing a contact to ground from the blade connector via thespring clip or, respectively, shielding unit up to the printed circuitboard connected to the spring clip, a spring contact that assumes thelocation of a signal contact 2 of the respective column is inventivelyprovided in the shielding unit 3. This spring contact can beadvantageously held by insulation displacement contacts 9 and 10 lyingopposite that are respectively fashioned at the ends of the groundlaminae 4, 5 at the side of the blade connector, as shown with referenceto various embodiments in FIGS. 1 and 2.

In the embodiment of FIG. 1, the spring contact 8 is fashioned withlateral shoulders 11 lying in longitudinal direction of the spring clip1, these thus enabling a retention by the insulation displacementscontacts 9 and 10 in a simple way and, thus, a reliable electricalconnection. The embodiment of FIG. 2 differs therefrom in that a broadlug 12 lying in longitudinal direction of the spring clip is fashionedtherein at that end of a contact leg of the spring contact 8 lying atthe blade connector side, said lug 12 being respectively held in turn atthe sides by an insulation displacement contact 9 and 10. The assemblygiven the embodiment of FIG. 1 ensues such that the spring contact 8 isfirst introduced in the insulator body of the spring clip 1 and suchthat the signal contacts 2 fashioned as signal spring contacts at theside of the blade connector are subsequently introduced. Respectivelytwo ground laminae are then bent interconnected as a bow andsimultaneously inserted between the signal spring contacts, whereby thecontacting to ground ensues at the insulation displacement contacts 9and 10. When assembling the shielding unit according to FIG. 2, thesignal spring contacts are first fitted in the insulator body of thespring clip; the ground laminae are subsequently inserted therebetweenand contacted to the lug 12 of the spring contact 8 with the insulationdisplacement contacts 9 and 10.

It is advantageous for practical applications when, as in theembodiments according to FIGS. 1 and 2, the middle signal contact 2 ofthe respective column is replaced by the spring contact 8 and by theground terminal 7. As can be derived from FIG. 1, the shielding unit 3with the spring contact 8 provided for the ground connection to theblade connector is introduced into every second column of the springclip 1. A respective opening 16 is thereby provided in the appertainingcolumns of the spring clip 1 for the spring contacts 8. Inventively, thecomplete column-by-column shielding of the signal contacts accordinglysucceeds with uniformly fashioned shielding units 3, whereby it isespecially advantageous that only one shielding unit is required per twocolumns. This yields the further advantage that only one signal contactper two columns need be occupied with ground. It is electrically morebeneficial when, as shown in FIGS. 1 and 2, when at least a secondpress-in ground terminal 12 is fashioned at the shielding unit 3. Theconfiguration in FIGS. 1 and 2 has proven optimum in several respects,whereby the bridge 6 is arranged at that end lying opposite the end ofthe shielding unit 3 at the side of the blade connector, and whereby thepress-in terminals of the respective signal contact column extendcolumn-like between the first ground terminal 7 lying behind thesepress-in terminals and the further ground terminals 13 lying in front ofthese press-in terminals. This proceeds more exactly from theconfigurations of the terminal bores on the printed circuit board shownin FIGS. 3 and 4. The terminals are placed or, respectively, shaped suchoverall that an optimum guidance of the reflux current is possible. Sothat the destranding with respect to the interconnects on or,respectively, through the printed circuit board is not made moredifficult, it is advantageous when the terminal bores for the groundterminals lie, as shown, in a line 14 at the front edge of the assemblyand/or behind the signal terminal rows 15. The position of a respectiveshielding unit 3 is also indicated in FIGS. 3 and 4. FIG. 4 also showsan alternative contacting wherein push contacts having a great plasticdeformability and an adequately great elastic restoring effect liebetween the signal terminal rows 15.

Accordingly, the inventive connector element is especially suited forcombination with a printed circuit board, whereby the press-in terminalsand the impressible ground terminals 7 and 13 extend into the printedcircuit board. Arrangements are thereby enabled that are composed of aninventive connector element or, respectively, of an inventivecombination with a spring clip printed circuit board and of acombination of a blade connector with a further printed circuit boardthat can be connected thereto by plugging. The invention can beespecially successfully employed in combination with the SIPAC(registered trademark) high-speed plug connector family of Siemens AG.

The invention is not limited to the particular details of the apparatusdepicted and other modifications and applications are contemplated.Certain other changes may be made in the above described apparatuswithout departing from the true spirit and scope of the invention hereininvolved. It is intended, therefore, that the subject matter in theabove depiction shall be interpreted as illustrative and not in alimiting sense.

What is claimed is:
 1. Printed circuit board connector element,comprising:a plurality of signal contacts arranged in a grid havingcolumns and rows in a spring clip of insulating material, the number ofrows being an odd number; a shielding unit having first and secondground lamina that are conductive, are arranged at opposite sides of atleast one of the signal contacts and that are conductively connected toone another via a bridge, the shielding unit having a first groundterminal projecting therefrom that can be conductively connected to theprinted circuit board; the ground laminae respectively extending overall intervening signal contacts of a column; the shielding unit beingprovided only for every second signal contact column; for each shieldingunit, an opening with an H-shaped cross-section which extends throughthe spring clip, the opening having thin lateral wings extending overthe entire column width of the spring clip; and the shielding unithaving a spring contact that assumes a position of the central signalcontact of the respective column.
 2. The connector element according toclaim 1, wherein the spring contact is held by insulation displacementcontacts respectively fashioned opposite at ends of the ground laminaeat a blade connector side.
 3. The connector element according to claim2, wherein the spring contact has a lateral shoulder lying inlongitudinal direction of the spring clip, said shoulders being held bythe insulation displacement contacts.
 4. The connector element accordingto claim 2, wherein a broad lug lying in longitudinal direction of thespring clip is fashioned at an end of a contact leg of the springcontact lying at the blade connector side, said lug being respectivelyheld at sides thereof by an insulation displacement contact.
 5. Theconnector element according to claim 2, wherein a middle signal contactof the respective column is replaced by the spring contact and by aground terminal.
 6. The connector element according to claim 1, whereinat least a second impressible ground contact is structured at theshielding unit.
 7. The connector element according to claim 6, wherein abridge is arranged at an end lying opposite an end of the shielding unitat the blade connector side; and wherein press-in terminals of therespective signal contact column extend column-like between a firstground terminal lying behind these press-in terminals and a furtherground terminals lying in front of these press-in terminals.
 8. Theconnector element according to claim 7, wherein the press-in terminalsand the impressible ground terminals extend into a printed circuit boardand wherein terminal bores for the ground terminals respectively lie onthe printed circuit board in a row in front of and behind the terminalbores for the press-in terminals of the signal contacts.